Abstract: A method of passive response communication, especially for an access control system, in which a first transponder (2) transmits an interrogation signal to a remote second transponder (3), which responds by transmitting data back to the first transponder (2), the two transponders each comprising a transmitter and a receiver, and a communication signal exchanged between said transponders (2, 3) in at least one direction including a plurality of anti-relay-attack pulses (13, 14). At least one distinguishing pulse (14) selected among the anti-relay-attack pulses has a distinctive shape and the receiver of said communication signal is selectively responsive to the shapes of said plurality of pulses (13, 14). Interception of the transmitted signal in a relay attack using digital transceivers will not relay the distinctive shape and the response of the second transponder is inhibited.

Abstract: A sensor device (20) comprises a sensor package (22) having a cavity (24) formed therein, a sensor die (26) mounted on a bottom surface (28) of the cavity (24) and a protective coating (30) formed over the sensor die in the cavity. The protective coating (30) is formed from a material, preferably a polymer material, which is arranged to have a graduated cross-linking density such that the material at the top of the cavity (24) has a high density of cross-linking and the material at the bottom of the cavity (24), which material is in contact with the sensor die, has a low density of cross-linking.

Abstract: A thermoplastic composition for a light-scattering shaped article comprises a transparent thermoplastic polymer, especially a (meth)acrylic (co)polymer and polyamide particles having an average size of from 0.4 to 200 .mu.m. A sheet obtained from the composition can be used in light display devices.

Abstract: A process for preparing a metal plastic composite comprising prime coating at least a portion of a metal substrate with one or more layers of an adhesion primer powder consisting of a solid thermosetting resin using a conventional powder application technique, heating the thus coated substrate to a temperature sufficient to melt a surface coating powder to be subsequently applied, immersing the thus coated substrate into a fluidized bed of a surface coating powder for a time sufficient to give the thickness of surface coating desired.

Abstract: The invention relates to a mixture in powder form and comprising (i) at least one polyamide and (ii) at least one polymer (A) containing hydroxyl functional groups and compatible with the polyamide. The polymer (A) may be an ethylene/vinyl alcohol copolymer. The mixture may be used to coat metal substrates.

Abstract: Thermoplastic powder coating compositions including a polyamide and/or polyetheresteramide constituent and an epoxy/sulfonamide resin constituent are well adapted for coating a wide variety of metal substrates, e.g., by electrostatic spraying, without the requirement for first treating such substrates with an adhesion primer.

Abstract: A device for measuring a physical quantity by time-division coding includes a source (1) capable of generating light pulses; a coder (2), the position of which depends on the value of the physical quantity, a sensor (4) including apparatus (5) for sending the light pulses to the coder (2) and a receiver (6) for receiving the coded light pulses, and an analyzer (7) for analyzing the coded light pulses connected to the sensor. The source (1) is capable of generating light pulses simultaneously at two different wavelengths (.lambda.1, .lambda.2), and the sensor (4) is provided with apparatus (9a) for separating the light pulses on the basis of their wavelength, the light pulses at a first wavelength (.lambda.1) passing through the sensor (4) and being coded, while the light pulses at a second wavelength (.lambda.2) are returned to the analyzer (7) to constitute pulses for triggering the sensor.